<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .parent {
            width: 300px;
            /* height: 300px; */
            background-color: #dbb1f9;
            /* 水平居中 */
            margin: 0 auto;
            display: flex;

        }

        .parent>div {
            width: 60px;
            height: 60px;
        }

        .parent>div:nth-child(2) {
            /* 给弹性元素设置宽度 默认值auto 优先级高于width */
            /* flex-basis: 100px; */
            /*flex： flex-grow flex-shrink flex-basis 
            默认值0 1 auto
            */
            flex: 1;
        }
        .parent>:last-child{
            flex: 2;
        }
    
    </style>
</head>

<body>
    <div class="parent">
        <div class="div1" style="background-color: rgb(223, 150, 234);">弹性元素1</div>
        <div class="div2" style="background-color: rgb(140, 186, 226);">弹性元素2</div>
        <div class="div3" style="background-color: rgb(239, 241, 143);">弹性元素3</div>
    </div>
</body>

</html>